| 摘要 |
<p>A non-return valve has a housing being symmetric with respect to a plane perpendicular to the direction of flow, and having facing inlet and outlet openings with surrounding identical valve seats, and identical bearing means adjacent each opening for holding a reversible valve flap. One flat side of the valve housing forms an inspection cover and, together with the opposite parallel flat side, carries the bearing means. Between the flat sides there extend parallel transverse sides and end sides which make an obtuse angle alpha with one transverse side and an acute angle with the other transverse side. One end side defines the inlet opening and the other end side the outlet opening.</p> |
